This is one of the most popular Scientifically Sweet recipes! This perfect small batch brownie recipe turns out perfect every time and takes just minutes to prepare!
Preheat oven to 350°F. Line a 9x5 or 8x4-inch loaf pan with parchment paper.
Melt together chocolate and butter in the microwave in short bursts with frequent stirring until completely melted, smooth and glossy.
Beat egg with sugar, vanilla and salt in a large bowl with a whisk or electric mixer for several minutes until pale, thick and fluffy. If using a mixer it will take 2-3 minutes. Beat in warm chocolate mixture until evenly blended. Sprinkle in flour and fold it in until well incorporated and smooth. Spread batter into prepared pan and sprinkle chocolate chips on top.
Bake for 16-24 minutes until a skewer inserted into the center comes out with a few moist crumbs. If you have a true 9x5-inch pan, the brownies should take just 16 minutes but if your pan is slightly smaller, they may need up to 25 minutes.